The chemical composition and antioxidant activities of basil from

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application of GC×GC, resulted in significantly different fingerprints for the two types ... Comprehensive two-dimensional gas chromatography (GC×GC) is a power- ..... H. B. Heath, Source book of flavor, Avi Publications, Westport, CT, 1981. 8.
J. Serb. Chem. Soc. 75 (11) 1503–1513 (2010) JSCS–4072

UDC 635.71+66.048+66.061+ 543.544.3:665.52/.54 Original scientific paper

The chemical composition and antioxidant activities of basil from Thailand using retention indices and comprehensive two-dimensional gas chromatography PATCHAREE PRIPDEEVECH1*, WATCHARAPONG CHUMPOLSRI2, PANAWAN SUTTIARPORN2 and SUGUNYA WONGPORNCHAI2 1School

of Science, Mae Fah Luang University, Chiang Rai, 57100 and 2Department Center of Excellence for Innovation in Chemistry, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand (Received 3 February, revised 12 June 2010) Abstract: The chemical compositions of essential oils obtained from Ocimum basilicum var. thyrsiflora (1.39 % dry weight) and Ocimum basilicum (0.61 %) were analyzed by GC–MS. Seventy-three constituents representing 99.64 % of the chromatographic peak area were obtained in the O. basilicum var. thyrsiflora oil, whereas 80 constituents representing 91.11 % observed in the essential oil of O. basilicum were obtained. Methyl chavicol (81.82 %), β-(E)-ocimene (2.93 %) and α-(E)-bergamotene (2.45 %) were found to be the dominant constituents in O. basilicum var. thyrsiflora oil while O. basilicum contained predominantly linalool (43.78 %), eugenol (13.66 %) and 1,8-cineole (10.18 %). The clear separation of the volatiles in all samples, demonstrated by the application of GC×GC, resulted in significantly different fingerprints for the two types of basil. The O. basilicum oil showed strong antioxidant activity while the oil of O. basilicum var. thyrsiflora exhibited very low activity, which was attributed to the significant differences in linalool and eugenol contents in these essential oils. Keywords: O. basilicum; O. basilicum var. thyrsiflora; DPPH radical scavenging activity; simultaneous distillation and extraction (SDE); comprehensive two-dimensional gas chromatography; GC×GC. INTRODUCTION

Basil (Ocimum basilicum), belonging to the Lamiaceae family, is one of the most popular plants grown extensively in many continents around the world, especially in Asia, Europe and North America. Basil is believed to have originated in Iran and/or India. At least 150 species of the genus Ocimum are widely * Corresponding author. E-mail: [email protected] doi: 10.2298/JSC100203125P

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cultivated in other countries of Asia.1 Although several basil species are found in many regions, the species O. basilicum is the most cultivated variety in the world.2–4 Basil has been planted as a popular culinary and medicinal herb from ancient time until now and the leaves and flowers have been used for the treatment of headaches, coughs, diarrhea, worms and kidney malfunctions, as well as for its carminative, galactagogue, stomachic and antispasmodic properties.1,5–7 Basil contains a wide range of phenolic compounds displaying various antioxidant activities, depending on the basil species and cultivars.8–11 The extracts of basil obtained by different methods are considered to be antimicrobial,12–14 insecticidal15 and useful in a number of medical treatments.16–18 The essential oils of basil are used in the flavoring of food and in perfumery because of their aromatic properties.19 There are significant differences in the chemical composition and amounts and kinds of aromatic components in the essential oils of basil depending on the species and environmental conditions of the cultivation location. For instance, basil having dark green leaves and white flowers, the popular cultivars for the fresh market and garden, possesses a rich spicy pungent aroma due to the presence of linalool, methyl chavicol and 1,8-cineole.19 Lesser cultivars vary in growth habit, size, and color, and can display a wide range of aromas including, lemon, rose, camphor, licorice, wood and fruit.19 The dark opal cultivar with purple color in all parts contains linalool and 1,8-cineole as the major components while camphor is dominant in the basil camphor cultivars.19 The basil cultivars of India, Pakistan and Guatemala exhibit methyl cinnamate as the dominant component.20,21 Basil essential oils include mainly the group of terpenoid components, which includes monoterpenes and sesquiterpenes as well as their oxygenated derivatives.22,23 The similarity of the structures of the constituents has obstructed component identification. To date, gas chromatography–mass spectrometry (GC–MS) has played the most important role in the identification of the chemical composition of basil essential oils. Nevertheless, incomplete identification was achieved by the use of GC–MS due to the complex nature of the constituents of the essential oil. Comprehensive two-dimensional gas chromatography (GC×GC) is a powerful technique that has been successfully used for the separation of the volatile constituents in highly complex samples, especially essential oils.24–26 This technique is a combination of two columns with different separation mechanisms coupled via a cryogenic modulator interface. Many co-eluting components on the first column are separated in the second column. This rapid technique displays significant differences between samples, making it a valuable technique for application in qualitative analysis. The application of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC– –TOFMS) has been employed to analyze the aromatic compounds of basil samples.27 Linalool, methyl chavicol, eugenol, and 1,8-cineole were the dominant com-

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pounds identified in these samples. The relative abundances of the different constituents allowed differentiation between the examined cultivars. In the present study, O. basilicum var. thyrsiflora and O. basilicum plants were grown in northern Thailand. The chemical compositions of the essential oils of the leaves of both cultivars were identified by using GC–MS and confirmed by the linear retention indices. The use of GC×GC with a longitudinally modulated cryogenic system (LMCS) was also employed to clearly differentiate between the fingerprints of these oil samples. Additionally, the analyses of the volatile constituents of all oils were completed by an evaluation and determination of the antioxidant activities of the essential oil samples. EXPERIMENTAL Plant materials and chemicals Aerial parts of two varieties of basil, O. basilicum var. thyrsiflora and O. basilicum, were collected at flowering stage in the Chiang Rai province located in the northern part of Thailand (altitude 390 m) in June 2008. Voucher herbarium specimens (QBG No. 41462 and QBG No. 41463) of O. basilicum var. thyrsiflora and O. basilicum plant, respectively, were identified and deposited at the Queen Sirikit Botanic Garden, Mae Rim, Chiang Mai, Thailand. The morphology of O. basilicum var. thyrsiflora and O. basilicum plants differ significantly. O. basilicum var. thyrsiflora plant has narrow green leaves, purple–red stems and violet pink flowers, whereas O. basilicum plant has light-green stems, elliptic–ovate leaves and white flowers. The leaves were separated by hand and then dried in the shade for 10 days before being subjected to simultaneous distillation–extraction (SDE). All basil essential oil samples obtained were diluted 1:10 v/v with n-hexane prior to injection into the GC–MS and GC×GC instruments. All chemicals were of analytical grade and consisted of dichloromethane, anhydrous sodium sulfate, mixtures of C8 to C22 n-alkanes and 2,2-diphenyl-1-picrylhydrazyl (DPPH) which were purchased from Merck (Darmstadt, Germany), and gallic acid, purchased from Sigma–Aldrich GmbH. (Steinheim, Germany). Gas chromatography–Mass spectrometry (GC–MS) The volatile constituents of basil leaf oils were analyzed using a Hewlett Packard model HP6890 gas chromatograph (Agilent Technologies, Palo Alto, CA, USA) equipped with an HP-5MS (5 % phenyl-polymethylsiloxane) capillary column (30 m×0.25 mm i.d., film thickness 0.25 μm; Agilent Technologies, USA) interfaced to an HP model 5973 mass-selective detector. The oven temperature was initially held at 100 °C and then increased at 2 °C min-1 to 220 °C. The injector and detector temperatures were 250 and 280 °C, respectively. Purified helium was used as the carrier gas at a flow rate of 1 mL min-1. The EI mass spectra were collected at an ionization voltage of 70 eV over the m/z range 29–300. The electron multiplier voltage was 1150 V. The ion source and quadrupole temperatures were set at 230 and 150 °C, respectively. Identification of volatile components was performed by comparison of their Kováts retention indices, relative to C8–C22 n-alkanes, and comparison of the mass spectra of individual components with the reference mass spectra in the Wiley 275 and NIST 98 databases and with the corresponding data for components in basil.10,19,28,29 Comprehensive two-dimensional gas chromatography (GC×GC) A gas chromatograph, model HP 6890, equipped with an FID detector and an HP 6890 series auto sampler was used for the GC×GC–FID experiments and was operated at 100 Hz

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data acquisition. The GC was retrofitted with a longitudinally modulated cryogenic system, LMCS (Chromatography Concepts, Doncaster, Australia). CO2 was employed as the cryogen, which was thermostatically controlled at about –20 °C for the duration of each run. The injection temperature was 250 °C with an injection volume of 1.0 µL in the split mode with a split ratio of 100:1. The injection and detector temperature were operated at 250 °C. Hydrogen gas was used as the carrier gas at a flow rate of 1.5 mL min-1. The GC was operated in the constant flow mode. The column set for GC×GC analysis consisted of two capillary columns which were serially coupled by a zero-dead-volume fitting. The column sets and operation conditions used in this experiment are listed in Table I. The columns are available from SGE International (Ringwood, Australia). The GC×GC column set BPX5/BP20 (Column set 1) was 5 % phenyl polysilphenylene-siloxane connected to a polyethylene glycol phase, which separates most components according to boiling point rather than polarity, while the separation polar/non-polar was obtained using the column set Solgel wax/BP1 (Column set 2) which is the combination of an inverse phase of poly(ethylene glycol) and 100 % dimethylpolysiloxane. Both column sets were selected to investigate the basil volatiles in all samples due to the different properties of these column sets. TABLE I. GC×GC column sets and temperature programs Set 1

Condition

1

Stationary phase Length, m Diameter, mm Film thickness, µm Modulation period, s Temperature program

D BPX5 30 0.25 0.25

Set 2 2

D BP20 2.0 0.10 0.10

6 from 120 to 180 °C at 1 °C min-1

1

D Solgel Wax 30 0.25 0.25

2

D BP1 2.0 0.1 0.10

6 from 80 to 250 °C at 2 °C min-1

Antioxidant activity DPPH radical scavenging assay. The radical scavenging abilities of O. basilicum var. thyrsiflora and O. basilicum essential oils based on reaction with the 2,2-diphenyl-2-picrylhydrazyl radical (DPPH˙) were evaluated by a spectrophotometric method based on the reduction of a methanol solution of DPPH according to a modified method of Blois.30 One milliliter of various concentrations of the each oil in methanol was added to 1 mL of a 0.003 % methanol solution of DPPH and the reaction mixture was shaken vigorously. The tubes were allowed to stand at room temperature (27 °C) for 30 min. Each reaction mixture was then placed in the cuvette holder of a Perkin Elmer-Lambda 25 UV/Vis spectrophotometer and monitored at 517 nm against a methanol blank. The scavenging ability was calculated as follows: scavenging ability = 100×(absorbance of control – absorbance of sample/absorbance of control). The antioxidant activity of all essential oils is expressed as IC50, which is defined as the concentration (in µg mL-1) of oil required to inhibit the formation of DPPH radicals by 50 %. The experiment was performed in triplicate. Determination of the total phenolic contents. Total phenolic content of the essential oils obtained from O. basilicum var. thyrsiflora and O. basilicum leaves was determined using Folin–Ciocalteu reagent according to a modified method of Singleton and Rossi31 using gallic acid as the standard. The oil solution (0.2 mL) was mixed with 1.0 mL of Folin–Ciocalteu reagent, 1.0 mL of a 7 % aqueous solution of Na2CO3 and 5.0 mL of distilled water. Then, the mixture was vigorously vortexed. The reaction mixtures were allowed to stand for 30 min

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before the absorbance at 765 nm was measured. The concentration of both essential oils was set to 5 mg mL-1. The same procedure was also applied to standard solutions of gallic acid. The calibration equation for gallic acid was: y = 0.00515x – 0.00400 (R2 = 0.999) where y is the absorbance and x is the concentration of gallic acid in mg mL-1. RESULTS AND DISCUSSION

The essential oil of the leaves of O. basilicum var. thyrsiflora and O. basilicum were extracted using a modified Likens–Nickerson apparatus and appeared as viscous yellow liquids with a percentage yield of 1.39 and 0.61 (w/w), respectively. These essential oils were subjected to detailed GC–MS analysis in order to determine the volatile constituents. Overall, 81 volatile constituents were identified among the two basil leaf oil samples. The GC–MS chromatograms of all samples are shown in Fig. 1. The structures of the volatile components identified by GC–MS, their relative area percentages and their retention indices are summarized in Table II. Although the oils of the two O. basilicum species contained high percentages of the same group of monoterpenes and sesquiterpenes, the different varieties presented significant variability in their chemical compositions. A total of 73 constituents representing 99.64 % of the O. basilicum var. thyrsiflora leaf oil were established. The dominant components were methyl chavicol (81.82 %), β-(E)-ocimene (2.93 %), α-(E)-bergamotene (2.45 %), α-epi-cadinol (2.08 %), 1,8-cineole (1.62 %), methyl eugenol (1.10 %) and camphor (1.09 %). As indicated, pentyl butanoate was distinguished only in O. basilicum var. thyrsiflora essential oil. The present studies are similar to the published research of Simon et al.,19 who reported methyl chavicol (60 %) and linalool (12 %) as the major constituents in the essential oil of O. basilicum var. thyrsiflora; Thai (Richters).

Fig. 1. GC-MS chromatogram of volatile component profiles of (1.1 above) O. basilicum essential oil, (1.2) O. basilicum var. thyrsiflora essential oil.

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TABLE II. Structural assignment and relative peak area percent of the volatile components of the essential oil obtained from of O. basilicum (A) and O. basilicum var. thyrsiflora (B) leaves LTPRIa

Component

Relative peak area, % A B 0.06 0.03 0.01 t 0.19 0.07 0.03 0.06 0.33 0.08 0.04 0.02 0.57 0.16 0.76 0.49

Component

LTPRI 1196 1253 1259 1283 1295 1344 1355 1358

Relative peak area, % A B 0.21 81.82 0.03 0.01 0.07 0.09 0.65 0.11 0.05 t 0.03 0.02 13.66 0.02 0.04 –

1373 1380

0.08 0.10

0.02 0.03

1385 1387 1391 1400 1410 1416 1420 1426 1431 1438 1442

0.06 0.47 0.05 0.09 0.09 0.08 0.04 t 0.10 0.05 0.05

0.03 0.31 0.02 1.10 0.04 0.06 0.02 – 2.45 0.05 0.03

1451 1454 1458

0.36 0.20 0.35

0.18 0.08 0.13

1462 1471 1477 1481 1485 1491 1611 1629 1640 1650 1652 1683

0.04 0.06 1.35 0.47 0.04 0.04 0.76 0.05 5.76 0.11 0.32 0.06

0.02 0.02 0.60 0.18 0.04 0.18 0.29 0.01 2.08 0.09 0.14 0.03

(E)-2-Hexenol α-Thujene α-Pinene Camphene Sabinene Amyl vinyl carbinol β-Pinene β-Myrcene

849 924 932 949 971 974 978 988

Dehydro-1,8-cineole para-Mentha-1(7),8-diene α-Terpinene ortho-Cymene Limonene 1,8-Cineole β- (E)-Ocimene γ-Terpinene (Z)-Sabinene hydrate Caprylyl acetate Terpinolene Linalool oxide Pentyl butanoate

991 1007

0.02 t

Methyl chavicol Geraniol Chavicol iso-Bornyl acetate Carquejol acetate α-Cubebene Eugenol exo-2-Hydroxycineole acetate 0.01 α-Ylangene 0.01 β-Bourbonene

1017 1024 1028 1033 1044 1056 1071 1078 1084 1087 1095

0.02 0.01 0.23 10.18 0.57 0.06 0.23 0.08 0.06 0.07 –

0.01 0.01 0.15 1.62 2.93 tb 0.03 t 0.15 – 0.01

Linalool (E)-Sabinene hydrate (Z)-Myroxide

1099 1099 1138

43.78 0.43 0.17 – 0.01 –

Camphor iso-Menthone δ-Terpineol Borneol Terpinen-4-ol γ-Terpineol β-(E)-Guaiene γ-Patchoulene β-Bisabolene γ-Cadinene (E)-Calamenene (Z)-Nerolidol

1146 1162 1170 1172 1179 1195 1498 1503 1505 1509 1516 1521

0.20 0.03 0.28 0.36 0.18 1.75 0.59 0.51 0.09 1.99 0.35 0.30

1.09 0.03 – 0.32 0.06 – 0.27 0.35 0.04 0.57 0.06 0.11

iso-Longifolene β-Elemene Cyperene Methyl eugenol α-Cedrene (E)-Caryophyllene β-Cedrene β-Copaene α-(E)-Bergamotene β-(Z)-Farnesene (Z)-Muurola-3,5-diene α-Humulene β-(E)-Farnesene (Z)-Muurola-4(14),5-diene β-Acoradiene γ-Gurjunene γ-Muurolene γ-Himachalene β-Selinene Bicyclogermacrene 1,10-Di-epi-cubenol β-Acorenol α-Epi-cadinol β-Eudesmol α-Cadinol α-Epi-bisabolol

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TABLE II. Continued Component

LTPRIa

α-Cadinene

1533 1560 1573 1579

Longicamphenylone Spathulenol (E)-Sesquisabinene hydrate β-(Z)-Elemenone a

1580

Relative peak area, % A B 0.03 0.01 0.08 0.02 0.25 0.03 0.01 – 0.06

Component

LTPRI

α-Bisabolol

1685 1698 1713 1889

Zierone β-(Z)-Santalol (E)-3-Tetradecen-5-yne

Relative peak area, % A B 0.10 0.04 0.03 t 0.12 0.03 0.24 0.05

0.03 b

Linear temperature program retention index; trace amount, < 0.005 %

Individually, O. basilicum leaf oil yielded 80 identified constituents representing 91.11 % with dominant components consisting of linalool (43.78 %) followed by eugenol (13.66 %), 1,8-cineole (10.18 %), α-epi-cadinol (5.76 %), γ-cadinene (1.99 %), γ-terpineol (1.75 %) and γ-muurolene (1.35 %), respectively. As can be observed, eight components (linalool oxide, (E)-sabinene hydrate, (Z)-myroxide, δ-terpineol, γ-terpineol, exo-2-hydroxycineole acetate, β-copaene and (E)-sesquisabinene hydrate) were detected only in the essential oil of O. basilicum. These results are in a good agreement with those of most published studies on the chemical composition of O. basilicum essential oil in which linalool was found to be the predominant constituent: Kéita et al.14 (69 %), Akgül32 (45.7 %) and Gurbuz et al.33 (41.2 %). In other studies, methyl chavicol (estragole) was represented as the major constituent in the O. basilicum leaf oils as can be seen in the study of Khatri et al.,34 Telci et al.10 and Chalchat et al.28 Additionally, methyl eugenol was detected as the main component in O. basilicum leaf oil in Thailand by Suppakul et al.29 These differences indicate that the chemical composition of the essential oils of O. basilicum varieties may be correlated with different environmental and ecological conditions, as well as by genetic factors. The overall volatile constituents of the basil leaf oil samples were analyzed using the GC×GC technique. In this study, the conventional combination of columns BPX5/BP20 (Column set 1) and columns Solgel wax/BP1 (Column set 2) were also employed (Table I). The essential oil of O. basilicum leaves was used for the optimization of the conditions in both column sets due to the higher number of components identified by GC–MS than for the oil obtained from O. basilicum var. thyrsiflora. The resulting GC×GC–FID contour plots obtained by the two column sets for all samples are shown in Fig. 2. The component separation in the Column set 1 was based on boiling point and polarity in first and second columns, respectively, but the separation was the reverse in the Column set 2. As seen in the contour plots in Fig. 2, at least 101 and 87 individual components of O. basilicum leaf oils were resolved by the use of Column set 1 and 2 as shown in

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Fig. 2. The contour plots of the volatile component profiles of: 1) O. basilicum essential oil with the polar–non-polar column set, 2) O. basilicum essential oil with the non-polar-polar column set and 3) O. basilicum var. thyrsiflora essential oil with non-polar–polar column set. The components are grouped into 3 groups: monoterpenes (A), sesquiterpenes (B) and oxygenated sesquiterpenes (C).

Figs. 2(1) and 2(2), respectively. This indicates that a better resolution was achieved by the use of Column set 1, in which many overlapping peaks were resolved in the 2nd dimension, allowing additional volatile components to be detected. The differentiations of the chemical composition among two varieties by the Column set 1 are present as contour plots shown in Fig. 2(2) and 2(3), respectively. At least 92 and 101 volatile components were detected in O. basilicum var. thyrsiflora and O. basilicum leaf essential oil, respectively. Nevertheless, using GC×GC, more compounds were found and separated compared to those obtained by GC–MS. Grouping of the various components are highlighted in the circled areas: A includes the monoterpenes, B includes the sesquiterpenes, and C

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includes the oxygenated sesquiterpenes. Although similar fingerprint patterns were exhibited in both essential oil profiles, the number of oxygenated monoterpenes (region A) of O. basilicum var. thyrsiflora essential oil was found to be significantly higher compared to that of the O. basilicum essential oil profile. The similar profiles of volatile sesquiterpenes (region B) in both essential oils are shown in Fig. 2(2) and 2(3), while numbers of oxygenated sesquiterpenes (region C) of O. basilicum essential oil were higher than that obtained from the essential oil of O. basilicum var. thyrsiflora. The antioxidant activities of the essential oils of O. basilicum var. thyrsiflora and O. basilicum leaves were tested by DPPH radical scavenging. The violet color of the radical disappeared when mixed with the substances in the essential oil solution that can donate a hydrogen atom. The antioxidant activities of all the essential oils and eugenol are presented in Table III, in which lower IC50 values indicate higher antioxidant activity. The O. basilicum essential oil (IC50 = = 26.53±0.94 µg mL–1) exhibited a higher scavenging ability for DPPH radicals than the essential oil of O. basilicum var. thyrsiflora (IC50 = 98.33±2.08 µg mL–1). The other results show that a stronger antioxidant activity was found with standard linalool (IC50 = 0.61±0.05 µg mL–1) and eugenol (IC50 = 2.83±0.08 µg mL–1) than with either of the essential oils. Thus an essential oil containing a higher level of linalool and eugenol should provide a stronger antioxidant activity as was found by Jilisni and Simon35 who reported that a stronger antioxidant activity was found in the essential oil containing a higher level of linalool. As a result, the O. basilicum essential oil was evaluated to be the stronger antioxidant than the essential oil of O. basilicum var. thyrsiflora according to the higher level of linalool and eugenol. The different levels of linalool and eugenol found between O. basilicum and O. basilicum var. thyrsiflora may be related to ecological conditions and genetic factors. TABLE III. Antioxidant activities of basil essential oils, standard linalool and eugenol IC50 / µg mL-1 (DPPH)a

Material O. basilicum leaf oil O. basilicum var. thyrsiflora leaf oil Linalool Eugenol a

26.53±0.94 98.33±2.08 0.61±0.05 2.83±0.08

Total phenolic contenta mg mL-1 0.102±0.009 0.070±0.004 –b –

b

Values represent averages±standard deviations for triplicate experiments; not studied

The amounts of total phenolic compounds in both the essential oils were investigated spectrometrically according to the Folin–Ciocalteu procedure, calculated as gallic acid equivalents. The essential oil of O. basilicum leaves contained higher amounts of total phenolic than that of O. basilicum var. thyrsiflora leaf oil, as can be seen in Table III. The total phenols of O. basilicum and O. basilicum

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var. thyrsiflora essential oil are 0.102±0.009 and 0.070±0.004 mg mL–1, respectively, at the same concentration of 5 mg mL–1. In the present study, linalool (43.78 %) and eugenol (13.66 %), the major components in the essential oil of O. basilicum, would play an important role in the antioxidant activity. The low amounts of linalool (0.43 %) and eugenol (0.02 %) in O. basilicum var. thyrsiflora oil are reflected in its relatively low antioxidant activity. CONCLUSIONS

Although the chemical compositions of the essential oils of O. basilicum var. thyrsiflora and O. basilicum leaves were similar, both oil samples had significant differences in their major constituents, as determined by GC–MS. In addition, GC×GC separation was utilized to monitor the profiles of both samples and good resolution was exhibited using a combination of non-polar and polar columns. Thus, this technique could be very useful for quality control during the industrial production of these essential oils. Finally, the high amount of linalool and eugenol in O. basilicum compared to O. basilicum var. thyrsiflora is likely responsible for the higher antioxidant activity of the former oil. Acknowledgements. Great appreciation is given to the Thai Royal Project for providing sweet basil (O. basilicum) and Queen Sirikit Botanic Garden for helpful collecting and identification of O. basilicum and O. basilicum var. thyrsiflora plant. Mae Fah Luang University is acknowledged for instrument support of the GC–MS and funding. The Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of Education, is also acknowledged for its support of the GC×GC system. ИЗВОД

ОДРЕЂИВАЊЕ ХЕМИЈСКОГ САСТАВА И АНТИОКСИДАТИВНЕ АКТИВНОСТИ БОСИЉКА ИЗ ТАЈЛАНДА ПРИМЕНОМ РЕТЕНЦИОНИХ ИНДЕКСА И ДВОДИМЕНЗИОНАЛНЕ ГАСНЕ ХРОМАТОГРАФИЈЕ PATCHAREE PRIPDEEVECH1, WATCHARAPONG CHUMPOLSRI2, PANAWAN SUTTIARPORN2 и SUGUNYA WONGPORNCHAI2 1

2

School of Science, Mae Fah Luang University, Chiang Rai, 57100 и Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand

Хемијски састав етарског уља босиљка Ocimum basilicum var. thyrsiflora (1,39 % у односу на суву масу) и Ocimum basilicum (0,61 %) је анализиран методом GC–MS. Седамдесет три састојка, која чине 99,64% укупне површине испод хроматографских максимума, нађено је у уљу O. basilicum var. thyrsiflora и осамдесет (91,11 %) у уљу O. basilicum. Метил чавикол (81,82 %), β-(E)-оцимен (2,93 %) и α-(E)-бергамотен (2,45 %) су главни састојци уља O. basilicum var. thyrsiflora, док уље O. basilicum садржи највише линалола (43,78 %), еугенола (13,66 %) и 1,8-цинеола (10,18 %). Добро раздвајање испарљивих састојака у свим узорцима, постигнуто применом GC×GC, указује на значајну разлику у саставу две врсте босиљка. Антиоксидативна активност уља O. basilicum је велика, док је активност уља O. basilicum var. thyrsiflora мала. Разлика у активности потиче од значајне разлике у садржају линалола и еугенола у ова два етарска уља. (Примљено 3. фебруара, ревидирано 12. јуна 2010)

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CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF BASIL

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